Environmentally benign catalysis

Synthesis and applications of phosphines in environmentally benign catalysis... 

Dartt, C.B. Davis, M.E. (1994) Catalysis for Environmentally Benign Processing. Industrial Engineering Chemical Research, 33, 2887-2899. 

As with carboxylic acids obtained by palladium hydroxycarbonylation, their derivatives esters, amides, anhydrides and acyl halides are synthesized from alkenes, CO and HX (X = OR, NR2 etc.). The Pd-catalyzed methoxycarbonylation is one of the most studied reactions among this type of catalyzed carbonylations and has been reviewed and included in reports of homogeneous catalysis.625, 26 The methoxycarbonylation has been applied to many different substrates to obtain intermediates in organic syntheses as well as specific products. For instance, the reaction has been applied for methoxycarbonylation of alkynes666 Highly efficient homogeneous Pd cationic catalysts have been reported and the methoxycarbonylation of alkynes has been used to develop economically attractive and environmentally benign process for the production of methyl... 

In particular the recent investigation as part of the project Smart Sol-vents/Smart ligands of the SLPC with PEG and ionic Hquids ( SILP ) as the catalyst carrier opened up new possibihties for the immobihzation of homogeneous catalysts. By increasing the stabihty of the catalytic performance, this concept may have the potential to be kept in mind for industrial catalysis in combination with environmentally benign supercritical or compressed carbon dioxide. In addition, this methodology is able to provide access to some chemical applications and processes because of the easy and facile preparation of the coated materials. 

The entries into transition metal catalysis discussed so far, required the presence of a specific bond (a polar carbon-heteroatom bond for oxidative addition or a carbon-carbon multiple bond for coordination-addition processes) that was sacrificed during the process. If we were able to use selected carbon-hydrogen bonds as sacrificial bonds, then we could not only save a lot of trouble in the preparation of starting materials but we would also provide environmentally benign alternatives to several existing processes. In spite of the progress made in this field the number of such transformations is still scarce compared to the aforementioned reactions. 

Catalytic Conversions in Water. An Environmentally Benign Concept for Heterogenization of Homogeneous Catalysis ... 

This review primarily focuses on the numerous reactions catalysed by water soluble transition metal complexes with emphasis on their implications for development of new environmentally benign processes in aqueous media based on the easy and quantitative separation of products from the catalyst as well as the avoidance of organic solvents. Moreover it contains, to our knowledge, the first comprehensive overview of water soluble ligands which play a key role for the development of efficient organometallic catalysis in aqueous media. 

Organometallic catalysis in biphasic aqueous/organic media is a novel and environmentally benign approach to combining the inherent advantages of homogeneous catalysts (high activity and selectivity) with the ease of separation... 

Finally, Drs. Georgios Papadogianakis and Roger Sheldon review catalysis in aqueous systems. These types of reactions are especially important in a new class of environmentally benign synthesis processes that are being developed in industry. 

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